CVE-2025-27110: Libmodsecurity3 has possible bypass of encoded HTML entities

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-02-25 · updated 2026-06-17
Weakness: CWE-172

Description

Libmodsecurity is one component of the ModSecurity v3 project. The library codebase serves as an interface to ModSecurity Connectors taking in web traffic and applying traditional ModSecurity processing. A bug that exists only in Libmodsecurity3 version 3.0.13 means that, in 3.0.13, Libmodsecurity3 can't decode encoded HTML entities if they contains leading zeroes. Version 3.0.14 contains a fix. No known workarounds are available.

Affected products

Trustwave Modsecurity: 3.0.13

References

https://github.com/owasp-modsecurity/ModSecurity/issues/3340
https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-42w7-rmv5-4x2j

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